Quote Originally Posted by Everyone in this thread
"Parsers do not modify anything, they are strictly read-only programs that collect data from the game and organize it for the user."
Quote Originally Posted by FFXIV User Agreement
"2.5 Data Mining.
You may not intercept, mine or otherwise collect information from the Game using unauthorized third party software."
/thread

If you guys want to argue the logic of such a rule and where it fits into the whole grand scheme of "fun enhancement," then that's another story. BUT until official word from SE says otherwise, parsers fall into the Data Mining category of in-game no-nos and anyone who tries to argue the opposite has no case to present.
Don't get me wrong, I am curious on what SE has to say on this issue. Maybe some of the arguments raised by both sides won't fall on deaf ears. Of course, you never know with SE, so I won't get my hopes up.